.headera{
    width:100%;  
    height: 10vh;
    background-color: #f2f2f2;  
}
.headera-left{
    float: left;
    margin-top: 1.5vh;
    margin-left: 1vh;
}
.headera>span{
    float: left;
    font-size: 2.5rem;
    color: #9999a1;
    margin-top: 1.5vh;
    margin-left: 22%;
}
.headera-right{
    float: right;
    margin-top: 1.5vh;
    margin-right: 1vh;
}
.headera img{
    width: 5vh;
    height: 5vh;
}
.middle{
    width: 100%;
    height: 10vh;
}
.middle ul{
    margin: 0;
    padding: 0;
}
.middle ul li {
    float: left;
    width: 25%;
    height: 10vh;
    text-align: center;
    list-style: none;
    padding-top: 20px;
    font-size: 1.5rem;
    color: #333333;
}
.banner_a{
    width: 100%;
    border-bottom: 15px solid #f5f5f5;
    border-top:15px solid #f5f5f5; 
}
.banner_a img{
    width: 100%;
}
.b-middle{
    width: 100%;
    text-align: center;
    height: 90vh;
}
ul{
    margin: 0;
    padding: 0;
}
ul li{
    width: 33%;
    float:left;
    list-style: none;
    /*margin-top: 4vh;*/
    height: 20vh;
}
ul li img{
    width: 60%;
    display: inline-block;
}

h1{
    font-size: 2rem;
    display: inline-block;
    padding-bottom: 2vh;
    color: #929292;
}
clear{
    clear: both;
}
.c-middle{
    width: 100%;
    text-align: center;
    height: 50vh;
}
.d-middle{
    width: 100%;
    text-align: center;
    height: 90vh;
}
.e-middle{
    width: 100%;
    text-align: center;
    height: 200vh;
}